Effect of seasonality on chemical profile and antifungal activity of essential oil isolated from leaves Psidium salutare (Kunth) O. Berg

Medicinal plants play a crucial role in the search for components that are capable of neutralizing the multiple mechanisms of fungal resistance. Psidium salutare (Kunth) O. Berg is a plant native to Brazil used as both food and traditional medicine to treat diseases and symptoms such as stomach ache and diarrhea, whose symptoms could be related to fungal infections from the genus Candida. The objective of this study was to investigate the influence of seasonal variability on the chemical composition of the Psidium salutare essential oil, its antifungal potential and its effect on the Candida albicans morphogenesis. The essential oils were collected in three different seasonal collection periods and isolated by the hydrodistillation process in a modified Clevenger apparatus with identification of the chemical composition determined by gas chromatography coupled to mass spectrometry (GC/MS). The antifungal assays were performed against Candida strains through the broth microdilution method to determine the minimum fungicidal concentration (MFC). Fungal growth was assessed by optical density reading and the Candida albicans dimorphic effect was evaluated by optical microscopy in microculture chambers. The chemical profile of the essential oils identified 40 substances in the different collection periods with γ-terpinene being the predominant constituent. The antifungal activity revealed an action against the C. albicans, C. krusei and C. tropicalis strains with an IC50 ranging from 345.5 to 2,754.2 µg/mL and a MFC higher than 1,024 µg/mL. When combined with essential oils at sub-inhibitory concentrations (MIC/16), fluconazole had its potentiated effect, i.e. a synergistic effect was observed in the combination of fluconazole with P.salutare oil against all Candida strains; however, for C. albicans, its effect was reinforced by the natural product in all the collection periods. The results show that the Psidium salutare oil affected the dimorphic transition capacity, significantly reducing the formation of hyphae and pseudohyphae in increasing concentrations. The results show that P. salutare oil exhibits a significant antifungal activity against three Candida species and that it can act in synergy with fluconazole. These results support the notion that this plant may have a potential use in pharmaceutical and preservative products

REFLEXÕES SOBRE MEMÓRIA DE TRABALHO E MEMÓRIA ORGANIZACIONAL NO ÂMBITO DA GESTÃO DO CONHECIMENTO

Este artigo tem por objetivo apresentar e desenvolver algumas reflexões sobre as relações entre memória de trabalho (MT) e memória organizacional (MO) na perspectiva da gestão do conhecimento (GC), levandose em conta os conceitos de criação, estruturação e disseminação do conhecimento. Partindo de abordagens teóricas sobre GC, resgatam-se os conceitos de memória individual especialmente o de memória de trabalho para buscar compreender como a MT, no plano pessoal, possibilita a construção da MO, que é decorrência dos processos de aprendizagem organizacional.Palavras-chave: gestão do conhecimento; aprendizagem organizacional; memória de trabalho (MT); memória organizacional (MO)

Trocas gasosas e fluorescência da clorofila em plantas de berinjela sob lâminas de irrigação

RESUMOA berinjela tem grande importância nutricional e socioeconômica, sendo cultivada e comercializada em vários países, principalmente em ambiente protegido; sua produção, assim como a de inúmeros cultivos agrícolas, é dependente de fatores como água, nutrientes e luz; propôs-se, assim, com este trabalho, avaliar as trocas gasosas, fluorescência da clorofila a e temperatura foliar de berinjela cultivada em ambiente protegido em diferentes lâminas de irrigação. O estudo foi realizado em casa de vegetação utilizando-se delineamento inteiramente casualizado, com 5 tratamentos e oito repetições, totalizando 40 unidades experimentais. Os tratamentos constaram de cinco lâminas de irrigação: 33, 66, 100, 133 e 166% da ETc, as quais corresponderam a 133, 266, 403, 536, 669 mm planta-1 ciclo-1, respectivamente. A taxa fotossintética das plantas de berinjela aumenta com o acréscimo da reposição hídrica. Os valores mais expressivos de trocas gasosas (A, E, gs, Ci, EiUA e EiC) nas plantas de berinjela, de forma geral, foram observados quando se utilizaram, na irrigação, lâminas estimadas entre 123,52 e 166% da ETc. A fluorescência da clorofila aumentou com o aumento das lâminas de irrigação e a temperatura foliar diminuiu em função do aumento da água

BioTIME:a database of biodiversity time series for the Anthropocene

Abstract Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community‐led open‐source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record. Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km² (158 cm²) to 100 km² (1,000,000,000,000 cm²). Time period and grain: BioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year. Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates. Software format: .csv and .SQL

Are rare species useful species? Obstacles to the conservation of tree diversity in the dry forest zone agro-ecosystems of Mesoamerica

Aim To test the potential to conserve rare dry forest tree and shrub species circa situm.Location Oaxaca, Mexico and Southern Honduras.Methods Local uses (timber, posts and firewood) of species were determined principally through semistructured interviews with 20 rural householders in each of four communities in Honduras and four in Oaxaca. Tree and shrub diversity inventories were carried out in a total of 227 forest patches and parcels of farmland in those eight communities. Species’ conservation priorities were determined using the star system of Hawthorne (1996) and IUCN listings.Results Despite a large number of useful species, remarkably few were also conservation priorities. Useful species were found to be substitutable as is illustrated by Bombacopsis quinata, Cordia alliodora, Guaiacum sanctum and G. coulteri.Conclusions In these areas, circa situm conservation is inhibited by the lack of species that are both rare and useful. Usefulness must be interpreted as a function of substitutability. Natural regeneration provides an abundance of diversity, farmers are unlikely to invest in the management of a species when suitable substitutes are freely available. The key to conserving rare species may be in maintaining or enhancing the value of the landscape elements in which they are found